Fred w



F. W. WOLF.

EXPANSION VALVE.

APPLICATION FILED SEPT. II. 1914.

Patented Aug. 26, 1919.

vii-W 71/ UNITED STATES PATENT OFFICE.

FRED W. WOLF, OF CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS, TO THE ISKO COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE.

EXPANSION-VALVE.

Specification of Letters Patent.

Patented Aug. 26, 1919.

7 '0 all whom it may concern Be it known that I, Finn) W. Wonr, a citizen of the United States, and a resident of Chicago, in the county of Cook and State of Illinois, have inv nted certain new and useful Improvements in Expansion-Valves; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying rawings. and to the letters of reference marked thereon, which form a part of this specification.

This invention relates to. improvements in valves, commonly known as expansion valves, such as are used to control the supply of a refrigerant to the expansion coil or chamber in a refrigerating apparatus. The invention consists of the matters hereinafter described and more particularly pointed out in the appended claims.

As is well known, in a refrigerating apparatus, the refrigerant is supplied to the expansion coil from a condenser or receiver containing liquid refrigerant under high pressure. The passage of the refrigerant from the liquid receiver or condenser to the expansion coil is controlled by the expansion valve through which the refrigerant is allowed to pass in small quantities as it is needed. The refrigerant enters the expansion coil, after it has passed through the said valve and vaporizes and expands in the expansion coil or chamber so as to cool the air or other fluid surrounding the same, in a familiar manner. After the expanded refrigerant has performed its function in the expansion coil, it is returned under pressure to the liquid receiver or condenser wherein it is again converted into liquid form as usual.

In the drawings:

Figure 1 is a view in elevation of an expansion coil with my improved expansion valve in connection therewith.

Fig. 2 is a view on enlarged scale illustrating a vertical section through an expansion valve made in accordance with my invention.

Fig. 3 is a detail plan sectional view, the plane of the section being indicated by line 3-3 of Fig. 2.

Referring more in detail to that embodiment of my'invention illustrated in the accompanying drawing, 5 indicates an expansion coil, the inlet end 6 of which is suita ly connected with the discharge side f my improved expansion valve, indicated as a whole as at 7. The outlet end 8, of said coil is connected with the compressor or like part of a refrigerating apparatus by means of which the vaporized, expanded refrigerant is drawn from the expansion coil and converted to liquid form.

The expansion valve 7, as shown in the drawings, comprises the following parts 1-- 9 indicates a chambered plate and 10 a flat ring, the two being attached together by means of screws 11 clamping between them a disk or diaphragm 12 ofthin flexible metal. A packing ring 13 is interposed between the marginal part of the diaphragm 12 and the plate 9 to insure a gas tight connection between them.

The bottom of the Plate 9 is concave and forms a shallow chamber 9 above the diaphragm 12. 14 indicates a boss on top of the plate 9 which boss is provided with a vertically extending passage 15 located conccntrically with respect to the diaphragm 12. Said passa e constitutes the inlet of the expansion va ve and a pipe 16 that leads from the condenser or other source of liquid refrigerant (not shown), is secured in the upper end of said passage. 17 indicates the lower end of the passage 15 which opens into the chamber 9" above the diaphragm 12 and which is adapted to be shut off from the inlet end of the passage 15 by means of a valve 20 having a head 19 which closes on an annular seat 18 formed in said passage.

The valve 20 has a stem 21 which is threaded through the diaphragm 12 and through flat nuts 22, 23, which are placed on opposite sides of the diaphragm and act to rigidly connect the valve stem thereto. A lead washer 24 is preferably interposed between. the bottom surface of the diaphragm and'the nut 23, to prevent leakage in the connection between the valve stem and diaphragm.

In the boss 14 above the valve seat 18 is formed a transverse passage 25, which constitutes the outlet of the valve structure and which is connected with the inlet end 6 of the expansion coil 5. The passage 25 is connected by a passage 26 with the chamber 9' above the diaphragm. The passage 25 also communicates with the vertical passage 15 at a point above the valve seat 18 through a ported valve seat 27 which is gen= el'ally a ball valve 28. Said hall is held to its seat by an expansion coiled spring 2!) which is held in place by a sleeve Ill) threaded into the passage 25 adjacent to the passage 26. The valve 28 acts as a. safety valve. Should a pressure greater than that at which the system lH designed to operate develop from any cause in the inlet passage 15 of the expansion coil, said pressure will act to overcome the. pressure of the spring :29 and dislodge the ball valve 28 from its seat thereby connecting the said inlet passage directly with. the low pressure side of the apparatus, namely, the expansion coil, thus imn'iediately relieving the pressure. When the pressure therein again falls to normal, that is to say, to a point below the predetermined pressure of the spring 29, the ball 28 will be closed upon its seat.

The operation of my improved valve is follows:

Condenser pressure will of course always be exerted on the head 19 of the valve 20. The pressure in the expansion coil will be exerted on top of the diaphragm 12 while atmospheric pressure will maintain against the bottom slde of said diaphragm. Thus the operation of the diaphragm will depend upon the differential of pressure, between the atn'iosphere'and the pressure in the expansion coil. The atmospheric pressure being constant, naturally the opening and closing of the valve will depend upon the variation of the pressure in the expansion coil. The large difference in area between that of the valve head 19 and the top surface of the diaphragm 12, which is influenced by the pressure in the expansion coil, will thus make the valve sensitive to every slight variation in the pressure in the expansion coil upon one or the other side of a certain pressure, irrespective of the condenser pressure.

My expansion valve as illustrated herein is designed more particularly for use in connection with a refrigerating apparatus in which S0 is used as the refrigerant. This for the reason that in the case of SO;

a temperature of about 26 F. in the Chill her in which the expansion coil is located, corresponds to about 15 F. of temperature 1n the expansion coil itself and this temperaturecorresponds to substantially atmospheric pressure in the expansion coil. Thusthe pressure of the atmosphere on the bottom of the diaphragm may be made use of as the constant pressure in producing a differential pressure on the diaphragm, thus doing away with springs,'weights, and similar devices, which while intended to be constant, are fOF-VaIIOHS reasons not constant" in theiraetion and require adjustment.- VVh1le inthe above I have referred. to

SO as the refrigerant, itwill be understood that the valve is equally capable of use to the same advantage with other refrigerants, it being simply necessary in the case of the use of such refrigerant, to so design the apparatus that it will operate to pro- (lure the required temperature in the c0mpartment in which the expansion coil is located with zero pounds or atmospheric pressure in the expansion coil.

One advantage of this valve is, that in a refrigerating apparatus where a device or other movable part requiring a stuffing box is used on the low pressure side of the apparatus, only zero pounds pressure (that is to say, atmospheric pressure) will be exerted against the stufling box, thus making it possible to use a stufling box preventing the escape of the refrigerant into the outside atmosphere therethrough, and reducing the friction loss of the refrigerating apparatus due to the use of such stufiing box.

Another advantage of this expansion valve is, that by its use a comparatively large opening is intermittently produced for the )assage of the liquid refrigerant from the high to the low pressure side of the system, thus eliminating the small openings heretofore used in expansion valves which were apt to be clogged up by foreign matter such as scale, oil, wasti nd the like.

Other advantages resist from the use of my expansion valve, which will be manifest to those familiar with the art. As is well known if the refrigerating apparatus is so designed that the required temperature in the compartment to be cooled, as in the di rect expansion system, is produced only when the refrigerant is much below zero pounds or atmospheric pressure, in case of any leaks in the coil, air will be driven into the coil which will interfere with the proper operation of the apparatus. On the other hand if the required temperature is produced in the coil with the refrigerant at a pressure substantially above atmospheric pressure, the refrigerant itself in case of leaks in the cOil will permeate into the compartment containing the foods or other articles in the refrigerator.

The primary object of the valve as stated above as one of the advantages, namely, to provide a valve which will operate at substantially atmospheric pressure in the expansion coil so that all pressure against the stufling box and in the expansion coil itself will be eliminated, thus preventing leaks either in or out, both at the stulfiing boxand expansion coil.

It :will be manifest from the above that this valve will only operate when the refrigerant in the expansion coil is normally at or about zero-pounds gage pressure or 'atmos-' pheric pressure.

I claim as my invention:

1.-In a (refrigerating apparatus, an expansion valve for use between the condenser and the expansion coil, said expansion valve comprising a casing containing a chamber, a boss on said casing having a vertically and a horizontally arranged aperture, a flexible diaphragm attached to said casing forming one wall of said chamber and comprising a differential pressure member exposed on one side to the pressure in the expansion coil and on the other side to atmospheric pressure, the vertical aperture in said boss providing communication between the condenser and said chamber and having a valve seat formed therein, a valve adapted to close on said seat attached to said diaphragm, said valve being exposed to the pressure in the condenser and being of substantially smaller cross sectional area as compared to the differential pressure area of said diaphragm, said horizontal aperture in said boss having a valve seat formed therein, said aperture cOnstituting a by-pass connect ing the condenser and expansion coils, a second valve member adapted to close upon said seat, and resilient means retaining said valve on said seat against the normal pressure in the condenser.

2. In a household refrigerating apparatus, an expansion valve for use between the condenser and the expansion coil, said valve comprising a casing having an inlet and an outlet, a passage connecting the inlet and out-let, an expansion valve governing the flow of fluid in said passage adapted to open in the direction opposite to the flow and to open when the fluid pressure in the outlet falls below a predetermined amount, a second passage connecting the inlet and outlet and a .valve normally preventing flow of fluid in this passage adapted to open when the pressure in the inlet exceeds a predetermined amount.

In testimony that I claim the foregoing as my invention I aliix my signature in the presence of two witnesses, this 29th day of July, A. D. 1914.

' FRED W. WOLF. Witnesses:

T. H. ALFm-ms, KARL W. DOLL. 

